Do boys benefit from male teachers in elementary school?

boyThe scarcity of male teachers in elementary school has led to a debate on whether young boys require more male role models in school, and whether boys might be discriminated against by female teachers. A recent IZA Discussion Paper by Patrick A. Puhani (Leibniz University Hannover) suggests that such fears are unwarranted.

Using administrative data on the population of students and teachers in the German state of Hesse, Puhani estimates teacher gender effects on elementary school outcomes. The evaluation of within-school variation, however, which controls for school fixed effects, identifies virtually no effects of teacher gender at the end of elementary school (grade 4, age 10) on either the teachers’ recommendations for middle school type choice or the actual school type choice in Germany’s early tracking system.

The one exception is that boys might benefit slightly in terms of a higher school type recommendation when taught by a male teacher, although there is no such effect on actual school type choice, probably because parents have the final word on this matter. Nor do the teacher fixed effects models reveal any effects of being taught by a teacher of the same gender on either outcome variable.

Puhani thus concludes that his findings “should allay the concerns expressed in the global press that the increasing feminization of elementary school education might lead to systematic discrimination of boys.”

Download the paper (IZA DP No. 11139):

Read a more detailed summary in German.

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Economic costs of global warming

icebergClimate change is considered one of the major challenges of the 21st century. While politicians and scientists at the COP23 climate change conference in Bonn are currently debating the political implications, economists have looked into the various economic consequences of global warming. Three papers co-authored by IZA’s “Environment and Labor Markets” Program Coordinator Olivier Deschenes investigate the impact of rising temperatures on productivity, birth rates and mortality.

The authors of the most recent paper, Peng Zhang (Hong Kong Polytechnic University), Olivier Deschenes (UC Santa Barbara & IZA), Kyle C. Meng (UC Santa Barbara), and Junjie Zhang (Duke Kunshan University), analyze detailed production data from a half million Chinese manufacturing plants over 1998-2007 to estimate the effects of temperature on firm-level total factor productivity (TFP), factor inputs, and output.

Chinese manufacturing output could fall by 12% per year

The findings show that both labor- and capital-intensive firms are affected by high temperatures. According to the study, one day with temperature above 90 degrees Fahrenheit (32° C) reduces TFP by 0.56% and manufacturing output by 0.45%, or by $8,160 in 2007 dollars, for the average firm. Since the temperature effects on labor and capital inputs are not as pronounced, TFP losses in response to high temperatures appear to be the primary channel through which temperature alters manufacturing output.

Based on historical and projected future climate data, the authors calculate that until the 2040-2059 period, average temperatures in China will increase by 3.6°F (2.0°C). As the map shows, more extremely hot days are to be expected especially in eastern and southern China.


Change in days per year with temperatures above 90°F between 1998-2007 and 2040-2059 periods

For the Chinese economy, this means that climate change could reduce manufacturing output by as much as 12% annually by mid-21st century or by $39.5 billion in 2007 dollars if no adaptations are undertaken. If China’s manufacturing output share remains fixed at 32% of national GDP, those predicted climate-driven losses in manufacturing alone would reduce Chinese GDP by 3.8% annually by mid-century, according to the study.

Global warming also affects birth rates and mortality

The findings of IZA Discussion Paper No. 9480 show that demography is also affected by global warming. The authors, Alan Barreca (Tulane University & IZA), Olivier Deschenes, and Melanie Guldi (University of Central Florida), conclude that increased temperatures due to climate change may reduce population growth rates over the course of the century. They estimate the effects of temperature shocks on birth rates in the United States between 1931 and 2010 and find that additional days above 80°F (27° C) cause a large decline in birth rates approximately 8 to 10 months later.

For more information on this topic, see the IZA World of Labor article by Alan Barreca: Does hot weather affect human fertility?


A third paper by Alan Barreca, Karen Clay (Carnegie Mellon University), Olivier Deschenes, Michael Greenstone (University of Chicago), and Joseph S. Shapiro (Yale University) evaluates the relationship between rising temperatures and life expectancy. In the economics literature, hot temperatures have been associated with excess mortality due to cardiovascular, respiratory, and cerebrovascular diseases.

The paper shows that the mortality impact of days with a mean temperature above 80° F has declined by about 70% after the 1960s. The results show that the drop in mortality can almost entirely be explained by the adoption of residential air conditioning in the US. In contrast, electrification and access to health care were not significantly related to changes in the temperature-mortality relationship.

The authors conclude that existing technologies (such as residential air-conditioning) offer tremendous opportunities to mitigate the impact of climate change. At the same time, greater use of energy-intensive adaptations may speed up the rate of climate change because electricity production worldwide continues to be primarily driven by the combustion of fossil fuels. “The continued expansion of the renewable energy sector and the development of more efficient adaptation technologies should also be key components of the world’s climate change strategy,” says Olivier Deschenes.

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Low-skilled immigration causes human capital polarization in Italy

migrant-workers-1358036_960_720While there is a vast literature considering the labor market effects of immigration, less has been done to investigate how immigration affects the educational choices of young natives, especially in Europe.

A new IZA discussion paper by University of Padova researchers Giorgio Brunello, Elisabetta Lodigiani and Lorenzo Rocco looks at the impact of low-skilled immigration on the educational choices of young natives in Italy during the period 2006–2016. The case of Italy is interesting because the majority of immigrants originate from developing countries and are low-skilled. Also, immigration to Italy is a recent and rapidly growing phenomenon. During the period of interest, the average share of immigrants almost doubled, from 3.7 to 7 percent of the population.

Decreasing marginal benefits for intermediate education

The authors argue that one possible outcome of higher immigration is human capital polarization – or the contemporaneous increase in the share of natives with lower (less than high school and not in education) and higher education (enrolled in college or with a college degree). They document that polarization is not only a theoretical possibility but also an empirical fact. The evidence for Italy – stronger for males than for females – indicates that the recent inflow of low-skilled immigrants has increased the share of both lower educated and higher educated natives.

The study also shows that native males who choose not to invest in further education because of immigration are more likely to work in manual jobs and in the service sector. Native females are instead more likely to be inactive. In line with previous literature, natives who invest more in education because of immigration are less likely to choose STEM fields and more likely to enroll in “communication-intensive” fields.

Reduction of the middle class

The findings indicate that immigration is another source of polarization, as much as globalization and technological progress. The economic literature so far has emphasized the latter but has almost overlooked the former. In the setup of the paper, the polarization of educational choices is privately optimal, but has unpalatable aggregate consequences, because it reduces social cohesion by reducing the size of the middle class. Importantly, the less privileged class is unlikely to consist only of immigrants. By pushing many natives out of school too early, low-skilled immigration is contributing to the expansion of a native underclass.

These results raise questions about what sort of immigration policy a country should select. On the one hand, attracting cheap unskilled labor from abroad can help support an industrial structure that relies more on the price of labor than on technological innovation. On the other hand, by delaying innovation and by reducing the human capital investments of many natives, this policy can have negative consequences on long-term productivity and international competitiveness and contribute to economic decline.

Download the complete paper (IZA DP No. 11062):

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Fertility and the digital divide: More flexibility, more children?

The rapid diffusion of the Internet, and in particular of high-speed, broadband Internet, has characterized the life-changing digital revolution that began around the turn of the twenty-first century. The profound social and economic implications of the spread of the Internet have been highlighted since its inception by social science scholars. More recently, researchers have also started to focus on the effect that the Internet has on family life. Scholars interested in family and fertility have long been focused on the importance of technological change.

Shifts in contraceptive technology, alongside the development of household appliances and medical advances, have been pointed to as some of the preconditions for the massive reproductive changes and the parallel large increases in women’s education and labor force participation that took place in high-income societies during the last period of the twentieth century. The discussion on low fertility, however, has not as of yet focused on the role of broader technological change and how it could shape the future of demographics, with the digital revolution epitomizing such technological change.

DSL technology boosts fertility of highly educated women

In a new IZA discussion paper, Francesco C. Billari (Bocconi University), Osea Giuntella (University of Pittsburgh and IZA) and Luca Stella (Bocconi University and IZA) analyze the impact of the diffusion of high-speed Internet on fertility choices in a low-fertility setting, Germany.

The authors exploit an instrumental variable approach devised by Falck et al. (2014) relying on unique historical and technological peculiarities of the public telephone infrastructure in Germany which affected the diffusion of DSL technology throughout the country. Using data from the German Socio-Economic Panel (2008-2012), they show that DSL access increases fertility of 25-45 year-old women and that these results are largely driven by highly educated women. The rise in fertility mostly reflects an increase in the probability of having more than one child.

Internet access may help bridge competing work-life goals

Moreover, the researchers investigate the potential mechanisms underlying the relationship between Internet and fertility. Their results suggest that broadband may increase fertility by increasing the opportunities of working from home and/or working part-time. These effects may relax time constraints, especially among more educated women, thereby favoring the work-family balance. They conclude that broadband might introduce a “fertility digital divide,” allowing highly educated individuals to realize their fertility goals, while not improving the chances of low-educated individuals, who tend to be employed in less flexible occupations.

Download the paper (IZA DP No. 10935):

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Teenage daughters as a risk factor for divorce

Sullen exchanges, inexplicable silences and broken curfews can be part of life for parents of teenagers, but could this period be also a stress-test for parents’ marriages? A new IZA Discussion Paper finds that parents of teenage daughters are more likely to separate than parents of teenage sons. We wanted to know more from the authors, IZA fellows Jan Kabatek and David Ribar of the Melbourne Institute.


Jan Kabatek

What is the main finding of your paper?

Our research studied more than two million marriages in the Netherlands over twenty years and showed that divorce risks faced by Dutch couples are dependent on age and gender of their children. The risks increase with children’s ages up to the point when children reach adulthood, and parents of teenage daughters are at greater risk still.

Has this topic been researched before?


David Ribar

The associations between marital strains and children’s gender were first identified by American sociologists in the 1980s. Economic research followed later, and several studies in the United States have indeed found that parents with first-born girls are slightly more likely to divorce than parents with first-born boys. However, until now, there was no evidence from other developed countries which would confirm that daughters strained marriages, and the heterogeneity of the gender effect remained largely unexplored.

Your study uses registry data from the Netherlands. Why Dutch data?

Compared to the data used in most previous studies, the Dutch administrative records are advantageous in several ways. They allow us to analyze a very large pool of marriages, the sample selection issues are minimal, and the records themselves are exceptionally comprehensive. We can look at exact dates of weddings, births, and divorces and delve deeper than studies which relied on self-reports and people’s recollections. More importantly, the data also allow us to link all parents to their children and examine just how long after their birth the couples separated.

What was the most striking result?

We found that the gender effect does exist among the Dutch parents, however it is strictly confined to the teenage years. Up until the age of 12, the gender of the child has no influence on the divorce risks faced by the parents. It is only between the ages 13 and 18 that parents of first-born girls divorce more frequently than parents of first-born boys. This finding contrasts prior evidence from US censuses, which documented significant differences of divorce risks for American families with children aged 0-12.

How does the teenage effect translate into numbers?

Conditional on staying married throughout the first twelve years of the first-born’s life, the odds of divorce are 10.7% for parents of teenage boys, and 11.3% for parents of teenage girls. In relative terms, this means that parents with teenage daughters face 5% higher risks of divorce than parents with teenage sons. The effect peaks at the age of 15, when the risk faced by parents with daughters is almost 10% higher than the risk faced by parents with sons. In the following years, the differences narrow again, and they disappear once the child turns 19. A similar pattern is also found among second-born and subsequent children.

Does this mean that Dutch parents have a preference for sons?

We don’t think so. The null finding for families with young children goes against the standard son-preference hypothesis, which implies that the mere presence of male children would make the marriage stronger. Furthermore, son preference would also influence fertility levels, rendering them higher for families with first-born girls. However, similar to recent US evidence reported in another recent IZA discussion paper, we find the exact opposite: families with first-born girls have slightly fewer children than families with first-born boys.

So what are the reasons why daughters might raise divorce risks?

We do not find evidence supporting several other well-established arguments, such as the theory which assumes that boys are more vulnerable and their need of male role models makes fathers more committed to the marriage. The same is the case for a sex-selection theory which postulates that mothers whose marriages are more stressful may be more likely to give birth to a baby girl.

Instead, our findings suggest that the higher divorce rates are explained by strains in the relationships between some parents and their teenage daughters, possibly stemming from differences in attitudes to gender roles. This explanation is backed by analysis of a large survey of Dutch households, which asked families about their relationships and opinions regarding marriage, gender and parenting.

What did the families say?

Parents of teenage daughters disagreed more about the way they should raise their children, and expressed more positive attitudes towards divorce. They were also less satisfied with the quality of their family relationships. Teenage daughters, in turn, reported worse relationships with their fathers, though not with their mothers.

Dads just don’t connect with their daughters?

Such a statement would be taking the empirics too far. Our findings do, however, suggest that the relationship of the father and his daughter is an important piece of the puzzle.

In one exercise, we split the administrative sample into two groups, depending on whether the father did or did not grow up with a sister. Our hypothesis was that the fathers who had more experience relating to teenage girls via their sisters would experience fewer relationship strains with their own teenage daughters. This could occur because fathers with sisters may hold more egalitarian attitudes towards gender roles, or because they have a better understanding of teenage girls and their family interactions.

In line with this reasoning, we found that the fathers who grew up with sisters did not face any increase in divorce risks from teenage daughters. The gender effect only appeared among fathers who grew up without sisters.

Do other family characteristics play a role?

We looked at other characteristics that could indicate differences between the gender-role attitudes held by the parents and their daughters, such as the ages or immigration background of the couple. Here, we also found that the parents who are likely to hold more traditional attitudes towards gender-roles experienced higher increases of divorce odds from teenage daughters.

Are the increased odds of divorce from teenage daughters unique to Dutch married couples?

It doesn’t seem so. We find the same associations for Dutch couples in de facto relationships, and our analysis of the Current Population Survey confirmed their existence also among married couples in the US. Importantly, we show that while we cannot reject the existence of a small gender effect for US families with children aged 0-12, we can demonstrate that such an effect is clearly dominated by the disparity that emerges in the teenage years. Compared to the previous estimates of the gender effect for US families with young children, the teenage effect derived from the CPS data is more than ten times larger. It is also substantially larger than the teenage effect found in the Dutch data.

So should parents of girls be worried they might be destined for divorce?

Not really. Despite their relative significance during the teenage years, the differences in the divorce risks faced by families with boys and girls remain modest over the child’s lifetime. By the time their first-born children reached age 25, 311 of every 1,000 Dutch couples with daughters had divorced, which can be compared to 307 of every 1,000 with sons—a difference of only 4 divorces per 1,000 couples.

Furthermore, the finding of a null effect among fathers who grew up with sisters shows that the association between the children’s gender and divorce risk is not universal. That being said, our study does point to serious strains between some parents and their teenage daughters, and help us understand the factors contributing to family break-down.

What can parents do to reduce these risks?

Our results suggest that parents of teenage daughters would do well to adopt more egalitarian attitudes towards gender roles and a greater understanding of how conflicts could come up. Struggles with teenagers will still happen, but better preparation and knowledge of the wants and needs of their teenage daughters could reduce the strain between partners.

Providing our children with role models who have modern attitudes toward gender roles, and promoting open communication within the family unit may contribute to a lowering of the rate of divorce or separation.

Thank you very much!


Download the paper (IZA DP No. 11046): Teenage Daughters as a Cause of Divorce

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Countering absenteeism by bringing temporarily disabled workers partly back to work

Disability rolls have been rising for decades in many OECD countries, entailing both a substantial volume of labor withdrawn from the market, as well as heavy social security costs. This has led to increased attention on the trade-off between generosity towards those hit by a negative health shock and potential moral hazard problems that faces any social security system. Traditional responses to this trade-off have been to establish strong screening criteria or other gatekeeping policies, or to limit the level or duration of benefits.

Activation reform in Norway

A new IZA Discussion Paper by Øystein Hernæs (Institute for Social Research and IZA) tries to answer whether an activation strategy based on graded sickness insurance, i.e. requiring temporary disabled workers to be partly back at work to the extent possible, as opposed to any absence automatically being 100%, can help reduce absenteeism and curb the corresponding social security costs. The paper analyzes a program implemented in the Norwegian region of Hedmark in 2013 aimed at strictly enforcing an already existing requirement that an employee on long-term sick leave be partly back at work unless explicitly judged by a physician to be unable to work at all, irrespective of adaptions at the workplace.

Absenteeism goes down markedly

The results show that the program to make use of the partial work capacity of workers on long-term sick-leave reduced absenteeism by 12 percent and brought large savings to the social insurance system. The effects were remarkably similar across gender and age groups, and somewhat smaller in the construction sector. Hernæs finds evidence that the absence rate declined not only through exploiting the partial work capacity of temporary disabled workers, but also by speeding up the transition rate back to full-time work. Consistent with expectations, the largest decline occurred for absenteeism due to musculoskeletal disorders, the smallest for respiratory disorders, with diagnoses for psychological and other disorders in between.

Viable alternative to traditional policies

Such an activation strategy represents an alternative to traditional attempts at welfare reform involving stricter screening or reductions in generosity, and may be more compatible with already existing legislation and contractual obligations, as well as easier to find support for across political priorities, according to Hernæs.

Download the complete paper (IZA DP No. 10991):

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Can debt restructuring help households out of the debt trap?

bankruptcyDuring the last financial crisis, the indebtedness of households and the number of bankrupt households reached levels that had not yet been experienced on a worldwide scale. In such an environment of high private debt, the policy debate seems to have shifted from the establishment of an ex ante “optimal” bankruptcy regime to the implementation of “ex post” special policy programs to restructure the debt of households in financial distress. A large number of policy initiatives were launched to ease the restructuring of household debt.

One aspect that has received little attention is the impact of the debt restructuring on the ability of the household to escape from the debt trap. A new IZA Discussion Paper by Henri Fraisse (Banque de France) studies for the case of France how debt suspensions influence the re-filing for bankruptcy.

Strong but short-lived effect on the likelihood to re-default

The author finds that granting a household a two-year suspension of debt repayment significantly and strongly decreases the likelihood of a re-default. A suspension of debt repayment leads to a 36.9% decrease in the probability of a re-default over the seven years following the bankruptcy decision of the marginal household.

The figure below reports the magnitude of the impact of the suspension over the years that follow. The suspension appears to have a significant impact in the first four years on the probability of re-default, reaching its peak in the second year following the decision. Five years after the decision – conditionally on not having previously re-defaulted – the probability of re-default is the same whether or not the household benefits from the grace period. For these households, the grace period therefore does not further disincentive repayment, nor give sufficient relief to further decrease the risk of re-default.


Re-default effect of a two-year suspension of debt repayment over the years relative to the year of the bankruptcy decision (2008)


Key drivers: expenditure rate and characteristics of the credit providers

Fraisse then measures how the impacts depend on the characteristics of the filers. He finds higher re-default effects for the population of filers who are in more dire financial straits. Unemployed filers with very low incomes and higher levels of indebtedness are substantially less likely to re-default following a suspension of debt repayment. However, neither the number of creditors,  nor the dispersion of the debt – in sum, the overall debt structure – seem to lead to significantly different re-default effects. The collective restructuring that is offered by the bankruptcy process seems to compensate for the relative higher financial fragility of households with atypical debt structures.

One key driver of heterogeneous effects is the expenditure rate. Low levels of expenditure rates are related to a non-significant effect of debt suspensions, whereas the likelihood to re-default is 67% lower for the population in the top quartile of the expenditure rate distribution in comparison with the bottom quartile. Fraisse further observes noticeable heterogeneous effects among providers of consumer credits. Following a suspension, a customer of one bank has a 3 percentage point lower probability to re-default than a customer of another bank. These results suggest that some banks target more financially fragile households.

In sum, these results indicate the importance of debt restructuring programs to help households to escape poverty trap. They also underline the necessity of policy actions on budget counseling, as well as the importance of regulation of credit distribution to avoid both entering into bankruptcy and re-filing for bankruptcy.

Download the complete paper (IZA DP No. 11032):

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